Conventionally, a Controller Area Network (CAN) used in an on-board system is known as one of Local Area Network (LAN) communication standards. Usually, at a dealership utility, a malfunction diagnosis (diagnosis) for diagnosing an ECU included in an on-board system is performed by connecting a service tool to CAN of the vehicle using a data link connector.
As is well known, an ECU is able to wirelessly communicate with an external device. For example, an ECU that is communicable with a mobile device receives a remote operation via the mobile device, and functions as a remote operation device (refer to patent literature 1).
Further, an ECU, such as a Data Communication Module (DCM), is able to access to a wireless communication network and perform a wireless communication with an external remote tool positioned outside of the vehicle. The DCM performs a malfunction diagnosis to each of multiple ECUs that configure the on-board system using CAN of the vehicle.
Furthermore, it is well known that, in an on-board system, the diagnosis of the ECU can be carried out by both the service tool and the remote tool.
A data frame transmitted or received in CAN includes identification information (ID). The identification information has 11 bit (or 29 bit) data that indicate a priority of the data frame, use purpose, frame type, or the like. In International Organization for Standardization (ISO) communication protocol, the frame IDs (11 bits) from 0x700 to 0x7FF are defined as the diagnosis purpose frame ID.
As described above, in a communication protocol defined under each of various communication standards, only limited identification informations are used for diagnosis purpose frame. However, in the future, with a diversification of the diagnosis tools and an increase of the number of ECUs equipped to a vehicle, the available identification informations for diagnosis purpose may face a problem of depletion.
Further, each ECU needs to perform different processes according to a type of the received data frame. Thus, when the number of identification informations for diagnosis purpose increases with the diversification of the diagnosis tools, the diagnosis related process carried out by the ECU may become complicated.